A conventional double wall container is shown in FIGS. 5 and 6 in which FIG. 5 shows a planar view of the container and FIG. 6 shows a cross-sectional view of FIG. 5. That is, the conventional double wall container is constructed from a container main body (1) made of a thermoplastic resin sheet having bonded thereto an inner body (2) made of a thermoplastic resin sheet. This container is produced by, for example, bonding a separately formed container main body (1) and inner body (2), each being made of a thermoplastic sheet to each other to thereby form a space at the bottom, as disclosed in Japanese Patent Publication No. 20181/1980, or by bonding a breathable water absorbing sheet such as a non-woven fabric to a regularly projected and concaved bottom of a container made of a thermoplastic resin sheet to thereby form a space at the bottom, as disclosed in Japanese Utility Model Publication No. 34567/1981. However these conventional methods have disadvantages that productivity is low and production cost is high.